Secondary cell



Patented Nov. 1 3,. 1934 UNITED STATES SECONDARY CELL Edmundo Almclda, London, England, assignor of one-half to Arthur Du Cros, Sussex, England No Drawing. Application August 17, 1932, Serial No. 629,237. Renewed May 24, 1934. In Great Britain July 28, 1931 4 Claims. (Cl. 136-20) This invention relates to secondary cells or batteries and has for its chief object to provide a new or improved cell or battery of inexpensive manufacture, light weight and long life. The cell 5 or battery according to my invention is also practically free from corrosion eflects and is substantially resistant to leakage or deterioration on open circuit.

The secondary cell or battery according to the present invention is characterized by having as an essential component of its electrolyte and also of its electrodes a metal of a particular class, namely a metal having a continuous series of exides that have different electro-chemical energy 15. and are practically insoluble and practically stable in the electrolyte.

More specifically stated a cell according to the present invention comprises as a negative electrode a metal as aforesaid or a low insoluble oxide 2 thereof, and as positive electrode a higher insolu- P ble oxide of the same metal, whilst the electrolyte consists of a solution of a salt or salts of the said metal, with the optional addition of a soluble salt or salts of any other metal which has a higher 26 reaction energy.

As metallic oxides and metallic salt those of manganese are particularly suitable, but those of other metals falling within the above-mentioned class may be used, as for example nickel, cobalt 9 or lead.

, v If, in the case of the negative electrode, the I selected metal is attacked by water it may be coated or faced with its lowest insoluble oxide.

- I Alternatively, such oxide may be carried in or 1' .5 upon a suitable support such as a metal of lower 5 reaction energy. I remark, however, that the supporting metal, if not inert, will take part in the reaction, and therefore, when its energy, though lower is the closest in value to that of 0 the supported metal, the voltage will be the highest; thus, for instance, I may employ a negative electrode consisting of manganese monoxide supported upon or incorporated in metallic zinc.

In the case of the positive electrode the higher.

. 5 consisting essentially of manganese dioxide (suit ably supported on or embedded mechanically or chemically in a chemically inert but electrically conductive material); 'a negative electrode consisting of manganese monoxide deposited on zinc; and an electrolyte consisting of a solution of manganese nitrate, sulphate, or chloride.

The electrolyte may be in the liquid state or in any suitably absorbed form according to the purposes to which the cell is to be put.

The following represent the reactions and efiects of a cell composed as described in the preceding paragraph. Eflfects during discharge may be deduced by following the arrows from start to finish pointing to the right, and recharging effects may be deduced by following the arrows from finish to start pointing to the left.

Did. in Discharge I Charge Cal. Kg.

. 8 e I csitive. a 3Mn(OH)4(348.9 O.Kg)+Mn=-4Mn(0ml(460 +111. 1

Voltage -2.2

Stage II Positive. a mmonhcm oxp+mn=ammomicmo 0.1m +eo.o

Negative. I M 0 94s o. 01 120.40 0. M itotic... o. z iwmlcu 0.1m em;

.Net gain 70.6 Cal. Kg. Voltage us Stage I11 Positive. Mn=(0H)|(333.3 amnmwmmomms 0.1m a 5m 5% i a tglii' (94 8 0 +01 (1st 40 0 ix )szn imctuaw cxiwznwmicu 0.1m -o.4 1m gain 30.5 can. Voltage 0.79 i v Average integral voltage 1/8]: 0d! 0! the 1st and 2nd stages Voltage 1.90-

'What'I claim is:--

" g l. A secondary cell'c sting, in its condition of readiness for use, of a container, an electrolyte consisting of a soliitionof a salt of manganese,

a negative electrode containing a manganese oxide, and a positive electrode comprising a higher oxide of manganese.

2. A secondary cell consisting, in its condition 5 0.

electrolyte of a solution; of' anyof thelgr uil consisting of manganese nitrate, sulphate, and chloride. I

4. A secondary cell comprising in its condition of readiness for use, a container, a negative electrode consisting of manganese having an outer layer of its lowest oxide, a positive electrode comprising a higher oxide of the same. metal, and an electrolyte consisting of a solution of a salt of manganese.

EDMUNDO ALMEIDA. 

